Re: [css-ruby] What does it mean for "ruby-position: inter-character" to force writing-mode to be vertical?

On 12/15/2014 03:22 AM, Xidorn Quan wrote:
> On Thu, Dec 11, 2014 at 9:36 AM, Daniel Holbert <dholbert@mozilla.com
> <mailto:dholbert@mozilla.com>> wrote:
>      (1) Does this spec-text influence the *computed value* of the
>     'writing-mode' property? (I hope not; there's added complexity when
>     properties influence other properties' computed values on the same
>     element.)
> 
> Actually, I hope the answer is yes. I'm not quite sure which way is
> better, but we have had some style fixup like this, and I don't think
> it's a big problem to add one more rule there. The only problem might be
> that it would add memory footprint.
> 
> I feel that, if we don't do this, we need to maintain another path for
> this value, and handle inheritance ourselves.

That's fair.  Behind my "I hope not", I really just meant that I want to
avoid adding channels of inter-property influence, if they aren't
actually intended/needed, because they add complexity (and foil memory
optimizations, at least in Gecko, as you indicated). But, it sounds like
the influence may be both intended & needed here -- which is fine, as
long as it's clearly explained.

In this case, the desired inter-property influence seems to be:
   For any element with a computed "display" of
   "ruby-text-container" *and* a computed "ruby-position"
   of "inter-character", the UA must force the computed
   "writing-mode" to be $SOME_VERTICAL_WRITING_MODE.

>      (2) If the answer to (1) is "yes" (I hope not): is this "writing-mode"
>     computed-value influence restricted to elements with "display:
>     ruby-text",
[...]
> 
> If that is style fixup, then it certainly only influences elements with
> "display: ruby-text-container", since ruby-position is inherited by
> default, and author may specify it in an outer container.

(Right, sorry - I meant "ruby-text-container", not "ruby-text". Thanks
for the correction on that.)

Like you, I think the answer to question (2) should really be "yes".  My
point in asking it was to highlight that this needs clarification in the
spec.

Thanks,
~Daniel

Received on Monday, 15 December 2014 18:01:11 UTC